package com.example.navviewmodel;

import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;

public class MyViewModel extends ViewModel {

    private MutableLiveData<Integer> number;

    public MutableLiveData<Integer> getNumber(){
         if (number == null){
             number = new MutableLiveData<>();
             number.setValue(0);
         }
         return number;
    }

    public void add(int x){
        number.setValue(number.getValue() + x);
        if (number.getValue() < 0){
            number.setValue(0);
        }
    }
}
